PROJECT SUMMARY/ABSTRACT?Flow Cytometry and Cell Sorting Shared Resource The goal of the Flow Cytometry and Cell Sorting Shared Resource (FCCSSR) is to support SJCCC members by providing access to a wide variety of state-of-the-art flow cytometry equipment, services, expertise, and training. This includes provision of consultation regarding experimental design and interpretation of results, delivery of extensive training in the operation of high-end flow analyzers, and provision of 4 high-end analyzers for use by trained users. Dr. Richard Ashmun serves as the Director of the FCCSSR and is responsible for consultations with users, personnel supervision, training, instrument operation, and oversight of all aspects of the operation of this facility. Ashmun holds a PhD in biomedical engineering and has served as the highly successful Director of the FCCSSR since 1987. The FCCSSR staff includes three senior flow cytometry specialists and 5 other staff members. The staff operates 9 flow analyzers (4 provided for user operation) and 5 cell sorters. In the current reporting period the FCCSSR acquired 3 instruments: a BD Symphony analyzer, a BD Aria Fusion sorter, and an additional BD LSR II analyzer. The FCCSSR was used by 47 SJCCC members in FY17 and supported work from 4 of the 5 Programs (HMP, DBSTP, NBTP, and CBP). Among the SJCCC members using the facility, 77% (n=36) have cancer-related, peer-reviewed funding. This work resulted in 112 peer-reviewed publications, 34.8% from intraprogrammatic and 26.8% from interprogrammatic collaborations, with many in high-impact journals such as Nature, Cell, Lancet Oncology, and Blood. The contribution of the FCCSSR is exemplified by several key accomplishments. For example, the FCCSSR worked extensively with members of the HMP (Drs. Charles Mullighan, Tanja Gruber, Mary Relling, and William Evans) in studies of acute lymphoblastic leukemia and acute myeloid leukemia to isolate phenotypically characterized tumor cells for further study, track tumor progression in xenograft models, and isolate genetically modified populations using cell sorting. Additionally, the FCCSSR was an important part of work by the DBSTP, contributing to studies of cell cycle responses to drug treatment and the phenotypic characterization and isolation of osteosarcomas and other pediatric solid tumors. Future plans include testing of complex flow assays and evaluation of instrumentation for enhancement of current services, including possible expansion into additional areas such as image-based or mass cytometry. FCCSSR will continue working with SJCCC members to develop and validate new protocols, optimizing the use of new reagents, and expanding the repository of reagents available to users. Additionally, as the robustness and complexity of data emerging from the new instruments increases, the FCCSSR Director and Staff will dedicate more time for detailed consultations with users regarding flow techniques, will expand the in-house training program, and will carefully evaluate replacements for obsolete equipment through demonstrations, testing and discussions with end users and the FCCSSR Advisory Committee.